Ethernet

Ethernet is a type of network protocol that enables the transmission of digital information over connections of different types. It is the dominant networking technology for connecting devices within local area networks (LANs) and for connecting LANs to Wide Area Networks (WANs).

Ethernet devices share a single communication cable using a contention-based multiple access wavelength division multiplexing (WDM) topology, meaning that all connected devices share the cable and have to compete for its usage. In this type of network, devices are individually assigned their own unique address called a Media Access Control (MAC) address.

Ethernet is based on the Carrier Sense Multiple Access/Collision Detection (CSMA/CD) protocol, which ensures that the same transmission from one device is not sent to another via the Ethernet connection. In order to provide efficient communication, the protocol operates in multiple layers

At the physical layer, Ethernet devices connect through a variety of media such as twisted or shielded pair of wires to data link layer. At the data link layer, Ethernet communicates using frame-type structures. This layer of Ethernet defines the rules followed when two devices send information via frames, which identify the start of a packet, the source and the destination, and the data associated with the packet.

At the network layer, Ethernet operates using the Internet Protocol (IP) address. This layer serves as the crucial Internet routing layer, which enables routers to relay traffic between two computers or to other networks.

At the transport layer, Ethernet supports a range of higher-level protocols, such as Transmission Control Protocol (TCP), User Datagram Protocol (UDP), and Internet Control Message Protocol (ICMP). These protocols provide efficient communication, congestion control, and error control.

Ethernet is used to support a wide range of applications, from messaging and browsing to video conferencing and file sharing. It is widely used in modern computer networks, and is a key technology in the development of cloud computing.